CN115920161A

CN115920161A - Oxygenator

Info

Publication number: CN115920161A
Application number: CN202211053996.3A
Authority: CN
Inventors: 齐献山; 王东晓
Original assignee: Magassist Inc
Current assignee: Magassist Inc
Priority date: 2022-07-13
Filing date: 2022-08-30
Publication date: 2023-04-07
Also published as: WO2024011988A1

Abstract

An oxygenator is provided, which comprises a shell, a first end cover and a second end cover which are arranged at two ends of the shell, a first sealing layer and a second sealing layer which are formed in the shell, an oxygenation module and a temperature control module which are arranged in the shell. The first end cover and the second end cover are respectively provided with a first interface and a second interface, one of the first interface and the second interface is an oxygenation medium inlet, and the other interface is an oxygenation medium outlet. The first seal layer and the first end cap define a first chamber in communication with the first port, and the second seal layer and the second end cap define a second chamber in communication with the second port. The side wall of the oxygenation module is communicated with the blood inlet, and two ends of an oxygenation membrane wire contained in the oxygenation module respectively penetrate through the first sealing layer and the second sealing layer and are respectively communicated with the first chamber and the second chamber. The temperature control module is positioned at the downstream of the oxygenation module along the flowing direction of blood, and the side wall is communicated with the blood outlet.

Description

Oxygenator

Technical Field

The present invention relates to oxygenators.

Background

ECMO (Extracorporeal Membrane Oxygenation) is a medical device that performs gas exchange outside a patient body to realize artificial heart and lung so as to replace the heart and lung function of the patient body, and is often applied to complex operations such as cardiac arrest, heart and lung failure or organ transplantation.

The oxygenator is one of the core components of ECMO, which performs the function of lung and performs the work of exchanging carbon dioxide and oxygen in blood. As shown in fig. 1, in a conventional membrane oxygenator, for example, blood in a patient is pumped out and then enters the oxygenator through a blood inlet, and fresh oxygen enters a hollow oxygenating fiber bundle from a gas inlet. The exchange of fresh oxygen and carbon dioxide in blood is realized by diffusion of gas and blood on two sides of the oxygenation membrane wire. Therefore, oxygenation efficiency (mL/min) is one of the important index parameters for reaction oxygenator performance.

Oxygenators typically include a two-layer structure of heating membrane filaments and oxygenating membrane filaments. Conventional wisdom in the art suggests that elevated temperatures have an enhancing effect on oxygenation efficiency. Therefore, in order to improve the oxygenation efficiency, a method of heating first and then oxygenating is often adopted. Thus, based on this knowledge, as in the prior art structure described above, the heating membrane filaments are often placed on the inside, and the oxygenation membrane filaments are placed on the outside.

When the oxygenator works, blood passes through the gaps among the oxygenation membrane filaments, and the thickness of the oxygenation membrane filaments is the flowing length of the blood. Therefore, the thickness of the oxygenation membrane filaments is critical to oxygenation efficiency. Generally, oxygenation efficiency is positively correlated with the thickness of the oxygenation membrane filaments. How to achieve better oxygenation efficiency when the preparation cost is fixed; or, in other words, how to increase the oxygenation efficiency as much as possible when the amount of the oxygenation membrane filaments is constant is a new technical problem faced in the art.

In addition, blood pressure drop (mmHg) is an important parameter indicator as well as oxygenation efficiency. The blood is pumped out of the patient, oxygenated by the oxygenator, and returned to the patient. In the process, the flow of blood is subject to a pressure drop, i.e., a pressure drop, due to energy loss or flow resistance. It is desirable in the art for oxygenators to have as little blood pressure drop as possible while ensuring good oxygenation efficiency.

Second, during oxygenator operation, it is desirable that the amount of blood that is involved in extracorporeal circulation be small. For example, if an oxygenator requiring a large amount of blood perfusion is applied to an anemic patient or a smaller patient, such as a child, the extreme case may occur where the patient's entire blood is involved in the extracorporeal circulation, and even if the patient's entire blood is involved in the extracorporeal circulation, the oxygenator may not be able to meet the perfusion requirements of the oxygenator. It is clear that such a situation is undesirable. In addition, the blood perfusion amount of the oxygenator is large, and a large amount of perfusate is also needed in a perfusion and air exhaust stage (Priming) before the operation is deployed, so that the air exhaust time is greatly prolonged, and the deployment process of the operation is influenced. Therefore, it is an urgent need from the clinical practice to improve the structure of the oxygenator in order to reduce the amount of perfusion of blood as much as possible.

Further, during blood flow, there are two substantially perpendicular shunts, namely: the blood flows forward to the downstream while flowing into the oxygenation membrane filaments to enter the downstream oxygenation membrane filaments. And the blood inevitably has pressure loss in the process of flowing to the downstream region, and then leads to the blood to enter the problem of uneven pressure when oxygenating membrane silk in different positions.

Disclosure of Invention

Accordingly, the present invention is directed to an oxygenator that solves at least one of the above problems.

In order to solve the technical problems, the oxygenator provided by the invention comprises a shell, a first end cover, a second end cover, a first sealing layer, a second sealing layer, an oxygenation module and a temperature control module, wherein the first end cover and the second end cover are arranged at two ends of the shell, the first sealing layer and the second sealing layer are formed in the shell, and the oxygenation module and the temperature control module are arranged in the shell. The first end cover and the second end cover are respectively provided with a first interface and a second interface, one of the first interface and the second interface is an oxygenation medium inlet, and the other one is an oxygenation medium outlet. The first seal layer and the first end cap define a first chamber in communication with the first port, and the second seal layer and the second end cap define a second chamber in communication with the second port. The side wall of the oxygenation module is communicated with the blood inlet, and two ends of an oxygenation membrane wire contained in the oxygenation module respectively penetrate through the first sealing layer and the second sealing layer and are respectively communicated with the first chamber and the second chamber. The temperature control module is positioned at the downstream of the oxygenation module along the flowing direction of the blood, and the side wall of the temperature control module is communicated with the blood outlet.

Preferably, the first end cover is provided with a third interface, the second end cover is provided with a fourth interface, one of the third interface and the fourth interface is a temperature control medium inlet, and the other is a temperature control medium outlet. The first sealing layer and the first end cap define a third chamber fluidly isolated from the first chamber, and the second sealing layer and the second end cap define a fourth chamber fluidly isolated from the second chamber. Two ends of a temperature control membrane wire contained in the temperature control module respectively penetrate through the first sealing layer and the second sealing layer and are respectively communicated with the third cavity and the fourth cavity.

Preferably, the blood inlet is provided in the first end cap. The oxygenation module is of a cylindrical structure, and the inner side wall of the oxygenation module is communicated with the blood inlet. The temperature control module is also in a roughly cylindrical structure and is arranged outside the oxygenation module. The outer side wall of the temperature control module and the inner side wall of the shell are spaced to form a gap space, and the gap space is communicated with the blood outlet.

Preferably, the blood outlet is provided in the side wall of the housing, and the axis of the blood outlet is located inside a tangent line. The tangent line is a line which is positioned on the same side of the central axis of the shell with the axis, is parallel to the axis and is tangent to the outer wall of the shell. The offset distance of the tangent line from the axis is preferably 2 to 10cm.

Preferably, an acute angle corner section is formed between the blood outlet and the shell, and the acute angle corner section is in round angle or circular arc transition.

Preferably, the first end cap is formed with a substantially dome-shaped structure which bulges outward, the blood inlet communicates with the dome-shaped structure, and the dome-shaped structure is provided with the air outlet.

Preferably, no other arbitrary structure exists between the oxygenation module and the temperature control module.

Preferably, the ratio L/H of the thickness L of the oxygenation module in the radial direction to its height H in the axial direction is comprised between 0.525 and 1.562.

Preferably, a first separator is arranged in the shell, and the oxygenation membrane wire is wound outside the first separator. First barrier member is cavity tubular structure, and inner space and blood entry intercommunication, the lateral wall is equipped with the first hole that supplies blood to pass through. The casing is internally provided with a second isolating piece positioned between the oxygenation module and the temperature control module, the temperature control membrane wire is wound outside the second isolating piece, and the side wall of the second isolating piece is provided with a second hole for blood to pass through. The ratio of the volume of the first hole to the volume of the space occupied by the first spacer is α 1, the ratio of the volume of the second hole to the volume of the space occupied by the second spacer is α 2, and α 1 > α 2. Specifically, α 1 has a value of 0.452 to 0.951, and α 2 has a value of 0.311 to 0.849.

Preferably, a separation cone penetrating through the first isolating piece is arranged in the shell. Along the direction of second end cover directional first end cover, the clearance distance between separation awl outer wall and the first isolator inner wall reduces gradually.

Preferably, the first end cap is formed with a circumferential flange extending to the first sealing layer, one end of the first spacer is connected to the separation cone, and the other end is connected to the circumferential flange, and the circumferential flange and the first spacer define a blood diversion cavity for accommodating the separation cone. The blood diversion chamber includes a blood inlet region into which the separation cone partially extends. The blood inlet area is an area between the surface section of the blood diversion cavity, which is opposite to the first end cover, of the first sealing layer and the first end cover.

Preferably, the ratio of the volume of the separation cone protruding into the blood inlet region to the volume of the blood inlet region is between 0.293 and 0.726. The separation cone includes a first cone segment adjacent the first end cap, the first cone segment being at least partially located within the blood inlet region. The conical head of the first conical section passes beyond the first sealing layer into the circumferential flange, the distance between the conical head and the top of the blood inlet area being between 0.012 and 0.546 cm. The ratio of the distance between the conical head of the first conical section and the top of the blood inlet area to the height of the first conical section is between 0.009 and 0.237.

Preferably, the separation cone further comprises a second cone section adjacent the second end cap and connected to the first cone section, the second cone section being located partially within the first spacer. The taper angle of the first conical section is greater than the taper angle of the second conical section.

Preferably, the minimum effective flow area of the blood inlet region is no less than the cross-sectional area of the blood inlet.

Under the traditional recognition, the oxygenation efficiency of blood after being heated is better. Therefore, in the existing structure, when blood flows through the oxygenator, the blood is firstly heated and then oxygenated. Generally, the longer the length of blood flow in the oxygenating membrane filaments, the better the oxygenation efficiency. The concept of improving the prior art is limited to increasing the length of blood flowing in the oxygenation membrane wire by increasing the thickness of the oxygenation membrane wire to achieve higher oxygenation efficiency, but this results in increased costs. The invention is that on the premise of not increasing the amount of the oxygenation membrane silk, the position of the oxygenation module is arranged at the upstream, and the flowing length of the blood in the oxygenation module is increased by reducing the inner diameter of the oxygenation module, so as to obtain higher oxygenation efficiency. That is, higher oxygenation efficiency is obtained under the condition of certain amount of the oxygenation membrane filaments (namely certain cost of the oxygenation membrane filaments). Alternatively, equivalent oxygenation efficiencies are achieved with low usage of oxygenating membrane filaments (corresponding to reduced oxygenating membrane filament cost).

The blood pressure drop inevitably occurs in the oxygenator, and is an important indicator of oxygenation efficiency. As the length of blood flow in the oxygenation module increases, the pressure drop of the blood also increases. The technical scheme disclosed by the invention seeks a balance between oxygenation efficiency and pressure drop on the basis of the first improvement. On the basis of certain consumption and certain height of the oxygenation membrane filaments, the ratio of the width to the height of the oxygenation membrane filaments is adjusted, so that lower blood pressure drop is realized while oxygenation efficiency is considered.

Drawings

FIG. 1 is a schematic diagram of a prior art hollow fiber membrane oxygenator;

FIG. 2 is a schematic view of a prior art oxygenator internal flow channel configuration;

FIG. 3 is a graph of oxygenation efficiency versus pressure drop;

FIG. 4 is a perspective view of an oxygenator in a preferred embodiment of the present invention;

FIG. 5 is a top view of the oxygenator shown in FIG. 4;

FIG. 6 is a side view of the oxygenator shown in FIG. 4;

FIG. 7 isbase:Sub>A cross-sectional view taken along line A-A of FIG. 6;

FIG. 8 is a cross-sectional view taken along line C-C of FIG. 5;

FIG. 9 is a schematic view of the flow conditions of the oxygenation medium;

FIG. 10 is a cross-sectional view taken along line B-B of FIG. 6;

FIG. 11 is a cross-sectional view taken along line D-D of FIG. 6;

FIG. 12 is a schematic view of a separation cone;

FIG. 13 is a cross-sectional view of another embodiment of the present invention showing a blood outlet;

fig. 14 is a cross-sectional view of an oxygenator in accordance with another embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the accompanying drawings. Those of ordinary skill in the art will recognize that the described embodiments can be modified in various different ways, without departing from the spirit and scope of the present invention. Accordingly, the drawings and description are illustrative in nature and not intended to limit the scope of the claims. Furthermore, in the present description, the drawings are not to scale and like reference numerals refer to like parts.

It should be noted that, in the embodiments of the present invention, the expressions "first" and "second" are used to distinguish two entities with the same name but different names or different parameters, and it is understood that "first" and "second" are merely for convenience of description and should not be construed as limitations of the embodiments of the present invention, and the descriptions thereof in the following embodiments are omitted.

Based on the conventional recognition of the effect of temperature on oxygenation efficiency, as shown in fig. 2, in a typical known embodiment, the membrane filaments of the oxygenator are of a double-layer columnar structure, the heating membrane filaments are layered on the inner side, and the oxygenation membrane filaments are layered on the outer side. The trace with arrows in the figure indicates the flow direction of blood. The blood flows to the heating membrane wire firstly and then flows to the oxygenation membrane wire, and the oxygenation process is finished.

The inventor of the present application found that the oxygenation efficiency of the oxygenator and the blood pressure drop have a curve relationship as shown in fig. 3. It is known that the blood pressure drop increases with increasing oxygenation efficiency. For example, when the oxygenation efficiency is greater than 270mL/min, the increase in blood pressure drop is greatly increased. From the results shown in fig. 3, the preferred embodiment of the present invention contemplates the design of the oxygenator to maximize oxygenation efficiency while seeking a reasonable range of pressure drop. I.e., the portion shown in fig. 3 by hatching, has the advantages of high oxygenation efficiency and small blood pressure drop.

As shown in fig. 2, in the design of the oxygenator with a double-layer cylindrical structure, the outer diameter of the oxygenation membrane filament layer is R, and the inner diameter is R. The flowing length of blood in the oxygenation membrane silk layer, that is, the thickness L of the oxygenation membrane silk layer in the radial direction satisfies the following relationship:

l = R-R formula (1)

The dosage V of the oxygenation membrane filaments and the axial height H of the oxygenation membrane filament layer satisfy the following relation:

H＝V/[π(R ² -r ² )]equation (2).

Based on the formulas (1) and (2), the positive correlation between the oxygenation efficiency and the thickness of the oxygenation membrane filaments is considered. Theoretically, a higher oxygenation efficiency can be obtained by increasing the thickness L of the oxygenation membrane filament layer. According to the formula (1), under the condition that the dosage V and the height H of the oxygenation membrane filaments are not changed, the inner diameter r of the oxygenation membrane filament layer is reduced, and the thickness L of the oxygenation membrane filament layer can be increased.

However, according to the conclusion of fig. 3, the blood pressure drop increases with increasing oxygenation efficiency. Therefore, in order to achieve both oxygenation efficiency and blood pressure drop, a larger thickness L of the filament layer of the oxygenation membrane is not always sought. But by adjusting the ratio of L/H.

Therefore, the inner diameter r of the oxygen layer can be reduced by incorporating the oxygenation module without changing the amount V and the height H of the oxygenation membrane filaments. Under the guidance of the technical spirit, the temperature control module is arranged downstream of the oxygenation module in the direction of blood flow. Then, after the blood enters the oxygenator, oxygenation is performed first and then temperature control is performed, contrary to conventional wisdom.

As shown in fig. 4 to 5, the oxygenator 100 of the present embodiment includes a hollow casing 10 opened at both ends, and a first end cap 20 and a second end cap 30 covering both ends of the casing 10. The first end cap 20 and the second end cap 30 are assembled with the first end and the second end of the housing 10, respectively, and form an oxygenator outline structure after being covered and fixed.

Two main working modules are arranged in the hollow shell 10, and are respectively: an oxygenation module for supplying oxygenation medium to circulate so as to oxygenate vein or anoxic blood, and a temperature control module for regulating the temperature of the blood. The oxygenation module comprises a plurality of wound oxygenation membrane wires, internal channels of the oxygenation membrane wires are used for allowing an oxygenation medium such as oxygen to pass through, and oxygenation is achieved when blood flows through gaps among the oxygenation membrane wires. The temperature control module regulates the temperature of the blood including warming, cooling, and warming, and may be of any suitable conventional construction, such as electrical heating, water bath coils, etc., or may be of a similar construction to the oxygenation module. Namely, the blood temperature control device is formed by winding a plurality of temperature control membrane wires, and temperature regulation of blood flowing through is realized by filling a temperature control medium such as water into the temperature control membrane wires. Wherein, the temperature of the water can be adjusted according to the temperature control requirement, for example, hot water is adopted when the temperature is increased.

The internal flow path of the oxygenator 100 is divided into three sections isolated from each other, respectively:

1) The oxygenation medium enters from the inlet, passes through the internal channel of the oxygenation membrane wire and is discharged from the outlet;

2) The temperature control medium enters from the inlet, passes through the internal channel of the temperature control membrane wire and is discharged from the outlet;

3) The blood flows in from the inlet, sequentially passes through the oxygenation module and the temperature control module, and then flows out from the outlet.

The internal channel of the oxygenation membrane wire forms a part of the oxygenation air passage, and the internal channel of the temperature control membrane wire forms a part of the temperature control flow passage. Blood passes through the gaps between the oxygenation membrane filaments, namely the outer side walls of the partial oxygenation air passages, so that oxygenation is realized. In a similar way, blood passes through the gaps of the temperature control membrane wires, namely the outer side walls of a part of the temperature control flow channels, so that temperature regulation is realized. As previously mentioned, the temperature control module is downstream of the oxygenation module in the direction of flow of the blood. Unlike the prior art and conventional wisdom, blood flow through the oxygenator of this embodiment is first oxygenated and then temperature controlled.

As shown in fig. 4, the first end cap 20 and the second end cap 30 are respectively formed with a first interface 21 and a second interface 31, both the first interface 21 and the second interface 31 are communicated with the oxygenation air passage, one of the interfaces is an oxygenation medium inlet, and the other interface is an oxygenation medium outlet. In the orientation presented in fig. 4, the first end cap 20 is disposed at the top of the housing 10 and the second end cap 30 is disposed at the bottom of the housing 10. And schematically, the first interface 21 is an oxygenation medium inlet, and the second interface 31 is an oxygenation medium outlet.

In the embodiment of filling the temperature control medium into the temperature control membrane wire for blood temperature control, the first end cap 20 and the second end cap 30 are further formed with a third interface 22 and a fourth interface 32, respectively. The third port 22 and the fourth port 32 are both in communication with a temperature controlled flow path, one of which is a temperature controlled medium inlet and the other of which is a temperature controlled medium outlet. The third port 22 includes an extension 221 on the first end cap 20, and a temperature-controlled joint end 222 extending outward from the extension 221, the extension 221 is recessed into the surface of the first end cap 20 at the edge, and the temperature-controlled joint end 222 is used for interfacing with the temperature-controlled pipeline. The structure of the fourth interface 32 is substantially identical to that of the third interface 22, and will not be described in detail. In the orientation presented in fig. 4, the fourth port 32, which is the media inlet, is located at the bottom and the third port 22, which is the media outlet, is located at the top. That is, the temperature control medium flows from bottom to top, in the opposite direction to the flow of the oxygenation medium.

The first end cap 20 has a blood inlet 23 formed thereon, and the blood inlet 23 includes an extension 231 and a connector end 232 extending outwardly from the extension 231. The extension 231 extends from the center of the first cap 20 in a radial direction and is recessed into the surface of the first cap 20, and the joint end 232 is used for interfacing with a blood transfusion line. The blood outlet 11 may be selectively disposed at any desired position, for example, on the second end cap 30 or on the sidewall of the housing 10. The blood outlet 11 includes an extension 111 and a tab end 232. The extension 231 of the blood inlet 23 and the extension 111 of the blood outlet 11 are each provided with a priming interface 233 for priming the blood entering and exiting the oxygenator 100 with anticoagulant.

As shown in fig. 5, the first end cap 20 is formed with a gas outlet 24, and the gas outlet 24 is built in with a waterproof breathable film (not shown). As shown in fig. 7, the extension 231 of the blood inlet 23 is eccentrically disposed with respect to the blood inlet area of the blood flow path inside the oxygenator 100. After entering the oxygenator 100, the blood rotates in the blood flow channel, and bubbles in the blood are removed under the action of centrifugal force, and the bubbles pass through the waterproof breathable membrane and are then discharged from the air outlet 24.

The internal structure of the oxygenator 100 is divided into three layers from inside to outside, which are: a separation cone 40 at the inner layer, a temperature control module 60 at the outer layer and an oxygenation module 50 in between, the three layers separated by a partition. Specifically, the separation cone 40 is separated from the oxygenation module 50 by a first partition 70 provided with a first hole, and the oxygenation module 50 comprises a filament of oxygenation membrane wound around the outside of the first partition 70. The first spacer 70 is substantially cylindrical, and the separation cone 40 is inserted into the first spacer 70, with a gap formed therebetween, which is in communication with the side wall of the oxygenation module 50 via a first hole. The oxygenation module 50 and the temperature control module 60 are separated by a second partition 80 provided with a second hole, a temperature control membrane wire contained in the temperature control module 60 is wound outside the second partition 80, and the oxygenation module 50 and the temperature control module 60 are communicated by the second hole. The spacing between temperature control module 60 and housing 10 forms an interstitial space that communicates with blood outlet 11.

As shown in fig. 8, a first sealing layer 12 is disposed in the housing 10 adjacent to the first end cap 20, and a second sealing layer 13 is disposed in the housing adjacent to the second end cap 30. The first sealant layer 12 may be formed within the housing 10 adjacent to the first end cap 20 or may be integrally formed within the housing 10 or the first end cap 20.

The first sealing layer 12 and the second sealing layer 13 are formed in the following manner: after finishing the winding of the oxygenation membrane yarn and the temperature control membrane yarn, putting the wound oxygenation membrane yarn and temperature control membrane yarn on a centrifugal machine together with a tool, connecting the tool with a sealant source, and starting the centrifugal machine. And under the action of centrifugal force, the glue enters the tool and plastically seals one ends of the oxygenated membrane filaments and the temperature control membrane filaments. After the completion, the direction is changed, the operations are repeated, and the other ends of the oxygenated membrane filaments and the temperature control membrane filaments are plastically packaged. And after the sealing glue is solidified, cutting the sealing glue at a position close to the outer side, cutting off the two ends of the membrane wire together, further forming a parallel and level surface on the outer surface of the sealing glue, and exposing the end part of the membrane wire to finish the manufacture of the sealing layer and the membrane wire.

A first chamber 91 is formed between the first sealing layer 12 and the first end cap 20 and a second chamber 92 is formed between the second sealing layer 13 and the second end cap 30. The first end cap 20 is formed with a first circumferential flange 25 on the inside and a second circumferential flange 26 on the outside, and the second end cap 30 is formed with a third circumferential flange 33 corresponding to the second circumferential flange 26. The first spacer 70 is connected at both ends to the first circumferential flange 25 and the separation cone 40, respectively, and the second spacer 80 is connected at both ends to the second circumferential flange 26 and the third circumferential flange 33, respectively.

The second circumferential flange 26 separates the cavity between the first seal layer 12 and the first end cap 20 into two isolated chambers and the third circumferential flange 33 separates the cavity between the second seal layer 13 and the second end cap 30 into two isolated chambers. The first chamber 91 communicates with the first port 21, the second chamber 92 communicates with the second port 31, the third chamber 93 communicates with the third port 22, and the fourth chamber 94 communicates with the fourth port 32. One end of the oxygenation membrane filament passes through the first sealing layer 12 to be communicated with the first chamber 91, and the other end passes through the second sealing layer 13 to be communicated with the second chamber 92. One end of the temperature control membrane thread penetrates through the first sealing layer 12 to be communicated with the third chamber, and the other end of the temperature control membrane thread penetrates through the second sealing layer 13 to be communicated with the fourth chamber.

As shown in fig. 9, the solid arrows show the flow trajectory of the oxygenation medium. The oxygenation medium enters the first chamber 91 from the first port 21, enters from the port of the oxygenation membrane filament located in the first sealing layer 12, exits from the port located in the second sealing layer 13 after oxygenation is completed, enters the second chamber 92, and finally exits from the second port 31. As shown in fig. 10, the solid arrows show the flow trajectory of the temperature control medium. The temperature control medium enters the fourth chamber 94 from the fourth port 32, enters from the port of the temperature control film filament located in the second sealing layer 13, is discharged from the port located in the first sealing layer 12 after temperature control is completed, enters the third chamber 93, and is finally discharged from the third port 22.

The separation cone 40 is a tapered cone structure extending in a direction in which the second end cap 30 is directed toward the first end cap 20, and a gap distance between an outer wall thereof and an inner wall of the first spacer 70 is gradually decreased in a direction in which the first end cap 20 is directed toward the second end cap 30. That is, the gap between the outer wall of the separation cone 40 and the inner wall of the first partition 70 is gradually decreased in the blood flow direction. As shown in fig. 11, the downward tapering gap may compensate for the pressure of the blood entering the oxygenation module. As described above, during the blood flow, there is a loss of pressure due to the simultaneous existence of two directional shunts or resistances, which results in the blood continuing to flow forward (downward as illustrated in fig. 11). To compensate for this loss, the gap is of a reduced design, and the blood, which has already lost pressure downstream, regains a high inflow pressure via the reduced gap, according to bernoulli's law of flow. Thus, the blood is forced to a uniform pressure throughout the sides of the oxygenation module as much as possible during the inflow process. Therefore, the pressure uniformity of the blood entering the oxygenation module is ensured to the maximum extent, and the oxygenation effect is improved.

The first circumferential flange 25 interfaces with the separation cone 40 through a first spacer 70. Thus, the first circumferential flange 25 and the first spacer 70 define therebetween a blood diversion lumen 41 that receives the separation cone 40 therein. The blood diversion lumen 41 includes a blood inlet area 411, as shown in fig. 7, the blood inlet area 411 is abutted with the extension 231 of the blood inlet 23, and the extension 231 and the blood inlet area 411 are eccentrically disposed. As shown in fig. 8, the blood inlet area 411 is the area between the cross section of the surface of the first sealing layer 12 opposite to the first end cap 20 and the first end cap 20 of the blood guiding chamber 41, and one end of the separation cone 40 protrudes into the blood inlet area 411. Also in view of compensating for the pressure drop occurring during the blood flow, the minimum effective flow area of the blood inlet region 411 is not smaller than the cross-sectional area of the blood inlet 23. The minimum effective flow area of the blood inlet region 411 is the area of the first sealing layer 12 at the cross section of the surface facing away from the first end cap 20 (shown as a dashed line in fig. 8).

As shown in fig. 11, the solid arrows show the flow trajectory of blood. Blood enters the blood inlet area 411 from the blood inlet 23, bubbles therein are removed under the action of centrifugal force, pressure is compensated by the tapered blood diversion cavity 41, the blood passes through the first holes on the first isolating member 70, oxygenation is completed through gaps between the oxygenation membrane filaments, the blood passes through the second holes on the second isolating member 80, and temperature control is completed through gaps between the temperature control membrane filaments. Then, it flows to the void space between the temperature control module 60 and the housing 10, and finally flows out from the blood outlet 11.

Under the premise that the amount V and the height H of the oxygenation membrane filaments are not changed, the internal diameter r of the oxygenation module 50 can be reduced by the oxygenation module 50, so that blood can have a longer flow length L, and the oxygenation efficiency is improved. Further, by adjusting the ratio of L/H, the pressure drop of the blood is brought within a desired range. Research and experiments show that when the ratio L/H of the thickness L of the oxygenation module 50 to the height H of the oxygenation module is 0.525-1.562, the oxygenator can give consideration to both oxygenation efficiency and pressure drop to the greatest extent. I.e. to obtain maximum oxygenation efficiency while minimizing the pressure drop of the blood.

It is noted that any numerical value in this disclosure includes all values from the lower value to the upper value that are incremented by one unit, and that there may be an interval of at least two units between any lower value and any higher value.

For example, ratios L/H of 0.525 to 1.562, further 0.575 to 1.512, further 0.625 to 1.462, and further 0.700 to 1.200 are set forth to illustrate equivalents such as 0.701, 0.786, 0.851, 0.889, 0.925, 0.963, 1.035, 1.152, 1.176 not expressly enumerated above.

As described above, the exemplary range of 0.05 as the interval unit cannot exclude the increase of the interval in an appropriate unit, for example, a numerical unit of 0.01, 0.02, 0.03, 0.04, 0.06, 0.1, 0.2, 0.3, 0.4, 0.5, etc. These are only examples of what is intended to be explicitly recited, and all possible combinations of numerical values between the lowest value and the highest value that are explicitly recited in the specification in a similar manner are to be considered.

For other definitions of numerical ranges appearing herein, reference is made to the above description and further description is omitted.

As described above with respect to the blood flow path, the blood passes through the blood guiding chamber 41 and then passes through the holes of the first and

second separators

70 and 80. In some embodiments, the ratio of the volume of the first pores to the volume of the space occupied by the first separator 70 is α 1, and the ratio of the volume of the second pores to the volume of the space occupied by the second separator 80 is α 2 (hereinafter referred to as porosity). The openings in the spacer should not be too small in diameter or create more resistance to blood flow and thus more pressure drop. Of course, the hole diameter of the opening on the isolating piece is not too large, otherwise the blood perfusion amount is increased.

Therefore, in order to achieve both pressure drop and perfusion, in this embodiment, α 1 has a value between 0.452 and 0.951, and α 2 has a value between 0.311 and 0.849. Further, α 1 has a value of 0.552 to 0.941, and α 2 has a value of 0.411 to 0.839. Further, α 1 has a value of 0.652 to 0.931, and α 2 has a value of 0.511 to 0.829. Still further, α 1 has a value between 0.752 and 0.921, and α 2 has a value between 0.611 and 0.819.

The need for both pressure drop and fill volume is as described above with respect to the porosity of both

separators

70, 80. However, due to the inner and outer layer relationship of the two spacers 70, 80 (for the embodiment of the cartridge oxygenation module and temperature control module), the porosity of the two

spacers

70, 80 is sized. Since the first separator 70 on the inner side has a smaller volume and circumferential area than the second separator 80 on the outer side, the porosity α 1 of the first separator 70 is greater than the porosity α 2 of the second separator 80 in order to provide the two

separators

70, 80 with substantially equal blood flow rates.

It should be noted that the above-mentioned porosity comparison and the range of values for the two

separators

70, 80 not only reduces the blood pressure drop and the volume of the oxygenator during operation, but also reduces the volume of the liquid perfusion fluid during the pre-operation degassing phase of the oxygenator. Therefore, the air exhaust time can be shortened, and the equipment can be quickly deployed.

As shown in fig. 8-10, to further reduce the blood perfusion volume, the ratio of the volume of separation cone 40 extending into blood inlet region 411 to the volume of blood inlet region 411 is between 0.293 and 0.726, further between 0.393 and 0.626, further between 0.433 and 0.596, and further between 0.493 and 0.586. In this way, a substantial portion of the space in blood inlet region 411 is occupied by separation cone 40, thereby reducing the amount of blood perfusion.

The above arrangement of the separation cone 40 can also reduce the liquid injection amount in the exhaust stage, which is not described in detail.

As shown in fig. 12, the separation cone 40 includes two cone segments, a first cone segment 42 adjacent to the first end cap 20 and a second cone segment 43 adjacent to the second end cap 30 and connected to the first cone segment 42. The first conical section 42 is located partially within the blood inlet region 411 with its conical head passing beyond the first sealing layer 12 into the first circumferential flange 25. The second cone section 43 is integrally formed with the second end cap 30, and a portion thereof is located inside the first separator 70, and another portion (the lower portion as shown in fig. 12) is located outside the first separator 70.

The conical head of the first conical section 42 is spaced from the top of the blood inlet region 411 by a distance M. The value of M is between 0.012 and 0.546 cm, further between 0.062 and 0.496 cm, further between 0.112 and 0.446 cm, and further between 0.212 and 0.346 cm. The ratio of the value of M to the height of the first conical section 42 is between 0.009 to 0.237, further between 0.019 to 0.227, further between 0.069 to 0.177, further still between 0.1 to 0.2.

The above definition of the distance M between the conical head of the first conical section 42 and the top of the blood inlet area 411 and the height ratio of the distance M to the first conical section 42 are also for reducing the perfusion amount of blood and liquid, and will not be described again.

The first conical section 42 is located mostly within the blood inlet region 411 and a small portion within the first partition 70, and the first conical section 42 serves to direct flow (downward flow as shown in fig. 12) and equalize entry into the blood inlet region 411. The second conical section 43 is located mostly inside the first partition 70 and its main function is to form the above-mentioned tapered gap with the first partition 70 for pressure loss compensation of the blood entering the oxygenation module.

In view of this, the taper angle θ 1 of the first tapered section 42 is larger than the taper angle θ 2 of the second tapered section 43. The clearance between the first tapered section 42 of lesser taper and the first circumferential flange 25 is greater than the clearance between the second tapered section 43 of greater taper and the first spacer 70. The relatively large gap formed between the first conical section 42 and the first circumferential flange 25 reduces the flow resistance of blood and thus the blood pressure drop, while the amount of perfusion can be significantly reduced by virtue of the first conical section 42 occupying the majority of the spatial volume of the blood inlet region 411 and the distance M between the conical head of the first conical section 42 and the top of the blood inlet region 411 as described above.

In the above embodiment, the oxygenation module 50 and the temperature control module 60 are substantially cylindrical, and the oxygenation module 50 is located inside the temperature control module 60. In such an embodiment, a blood inlet 23 is provided on the first end cap 20, which communicates with the inner side walls of the oxygenation module 50 through the blood inlet region 411 and the tapered gap formed between the separation cone 40 and the first partition 70. The blood outlet 11 is provided in a side wall of the case 10, and communicates with an outer side wall of the temperature control module 60 through a gap formed between the temperature control module 60 and the case 10. The axial direction of the blood inlet 23 is substantially parallel to the axial directions of the oxygenation membrane filaments and the temperature control membrane filaments. Specifically, the axial direction of the blood inlet 23 is substantially perpendicular to the axial direction of the housing 10, and the oxygenation membrane wires and the temperature-control membrane wires are disposed in the housing 10 in a substantially vertical state, that is, the axial directions of the oxygenation membrane wires and the temperature-control membrane wires are substantially parallel to the axial direction of the housing 10. As shown in fig. 9, the flow trajectory of blood in a unilateral section is roughly in the shape of "Contraband".

Of course, under the guidance of the technical spirit of the present invention of oxygenation before temperature control, the oxygenation module 50, the temperature control module 60 and the communication relationship between the two operation modules and the blood inlet 23 and the blood outlet 11 may have other possible embodiments, which are not limited to the above.

For example, in one possible embodiment, the oxygenation module 50 and temperature control module 60 are also cylindrical, except that the oxygenation module 50 is on the outside and the temperature control module 60 is on the inside. Accordingly, the blood inlet 23 is provided on a side wall of the housing 10, which communicates with an outer side wall of the oxygenation module 50 through a gap formed between the oxygenation module 50 and the housing 10. The blood outlet 11 is provided on at least one end cap, which communicates with the inner sidewall of the temperature control module 60 through the tapered gap formed between the separation cone 40 and the first partition 70 and the blood inlet region 411. The directions of the blood inlet 23, the oxygenation membrane filaments and the temperature control membrane filaments are the same as those of the previous embodiment, and are not described in detail. The flow trajectory of the blood is substantially shaped like a letter or an "plumb".

Alternatively, in another possible embodiment, the oxygenation module and the temperature control module are in the shape of a plate, a block or a layer with a certain thickness, and the oxygenation module and the temperature control module are arranged in a stacked manner. In contrast to the two embodiments described above, in this embodiment, a separation cone may not be necessary. However, to ensure the exhaust, the blood inlet is also eccentrically arranged to ensure that the blood at the inlet can generate a rotational flow to smoothly degas under the action of centrifugal force. The blood inlet and the blood outlet are located at two sides or opposite sides of the oxygenation module and the temperature control module, and may be respectively disposed on the two end caps, or may be disposed on the outer wall of the housing 10. The blood inlet communicates with the side walls of the oxygenation module through a gap or space between the oxygenation module and one of the end caps, e.g., the first end cap (similar to the blood inlet region 411 described above), and the blood outlet communicates with the side walls of the temperature control module through a gap or space between the temperature control module and the other end cap, e.g., the second end cap. The blood flow trajectory is substantially I-shaped or I-shaped.

In the embodiment illustrated in fig. 4 to 12, the blood outlet 11 is provided in the side wall of the housing 10, and the axis of the blood outlet 11 passes through the central axis of the housing 10. Fig. 13 provides an alternative arrangement of the blood outlet 11. In this embodiment, the axis of the blood outlet 11 is located inside a tangent line that is on the same side of the central axis of the housing 11 as the axis of the blood outlet 11, parallel to the axis of the blood outlet 11 and tangent to the outer wall of the housing 10. The distance between the axis and the tangent is determined in accordance with the actual situation, and is, for example, 2 to 10cm, further 3 to 9cm, further 4 to 8cm, and further 5 to 7cm. In practice, the blood outlet 11 is arranged in such a way that it is offset inwardly by a distance from a point on the housing 10 tangential to the housing 10.

It is noted that the tangentially arranged blood outlet 11 has a better hydraulic performance than the blood outlet 11 of the embodiment shown in fig. 4 to 12, which is demonstrated by known embodiments including, but not limited to, for example, US20200237994A1 and will not be described herein.

It is however noted that, as can be seen from the basic geometrical knowledge, a sharp corner is formed between the tangentially arranged blood outlet 11 and the housing 10, the presence of which corner causes a stagnation of blood with a low flow velocity, thus forming a thrombus. In practice, the amount of blood having a low flow rate is small in this portion, but once a thrombus is formed, the outflow of blood having a low flow rate is further inhibited, and the formation and enlargement of the thrombus are accelerated. In addition, once the thrombus is washed out by the blood with a fast flow rate and participates in circulation between an extracorporeal device such as a blood pump and a patient (extracorporeal circulation), the thrombus may cause injury to the patient, for example, the thrombus enters a blood vessel in the body of the patient and stays, which easily causes organ ischemia, limb necrosis and the like.

The strictly tangentially arranged blood outlet 11 does not allow for a design of the buffer structure with rounded or rounded corners at the sharp corners between it and the housing 10. The reason is that: the housing 10 with the blood outlet 11 thereon is formed by means of a mould, which needs to be removed after the manufacture is completed. The above-described buffer design cannot be realized because the blood outlet 11, which is arranged strictly tangentially, has no demolding space on the opposite side of the sharp corner.

In contrast, this embodiment is biased in parallel by the blood outlet 11, which is originally in a tangential position, being biased inwards. As mentioned above, the offset design does not lose hydraulic performance (not much in relation to offset distance) due to the smaller volume of blood with lower flow rate. By the offset, a demolding space is reserved, and the transition of an acute-angle corner section A formed between the blood outlet 11 and the shell 10 into a round angle or a circular arc becomes possible.

In the embodiment illustrated in fig. 4 to 12, the first cap 20 is formed with a substantially flat tapered shape communicating with the blood inlet 23 and provided with the exhaust port 24. In the embodiment illustrated in fig. 14, unlike the above-described embodiments, the structure 201 is outwardly convex and has a substantially dome or hemispherical shape. The raised dome-shaped structure 201 has a smoother inner wall than the flat cone-shaped structure, and properly pulls apart the distance between the cone heads of the separation cone 40. Practice proves that the structure 201 can provide time for floating of the removed bubbles and enable air to be exhausted more fully by enlarging the distance between the separation cone 40 and the cone head without increasing the blood perfusion amount obviously.

Further, in the embodiment illustrated in fig. 4 to 12, a second isolation member 80 is disposed between the oxygenation module 50 and the temperature control module 60, which mainly serves as a requirement of the manufacturing process of the temperature control module 60, as described above, and is not described in detail. In the embodiment illustrated in fig. 14, unlike the above-described embodiment, there is no other arbitrary structure between the oxygenation module 50 and the temperature control module 60. That is, the second separator 80 in the above embodiment may be eliminated. In the case of removing the second spacer 80, the manufacturing process of the temperature control module 60 is roughly: after the temperature control module is manufactured by winding the temperature control membrane wire by using the jig, the jig is pulled away, and then the wound cylindrical temperature control module 60 is sleeved outside the oxygenation module 50.

Since there are no other physical structural obstacles between the oxygenation module 50 and the temperature control module 60, like the second spacer 80, the gap distance between the oxygenation module 50 and the temperature control module 60 can be made small. In practice, due to the lack of retention by other physical structures like secondary spacer 80, the membrane filaments of the two modules may come into contact with each other due to loose expansion, thereby filling the space originally occupied by secondary spacer 80. Therefore, the structure design not only can reduce the blood perfusion amount, but also can remarkably reduce the blood pressure drop.

The above examples only show several embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent should be subject to the appended claims.

Claims

1. An oxygenator, comprising:

a housing;

the first end cover is arranged at the first end of the shell and is provided with a first interface;

the second end cover is arranged at the second end of the shell and is provided with a second interface; one of the first interface and the second interface is an oxygenation medium inlet, and the other is an oxygenation medium outlet;

a first sealing layer at least partially formed within the housing proximate the first end cap defining a first chamber with the first end cap, the first chamber in communication with the first port;

a second sealing layer at least partially formed within the housing proximate the second end cap defining a second chamber with the second end cap, the second chamber in communication with the second port;

the oxygenation module is arranged in the shell, the side wall of the oxygenation module is communicated with the blood inlet, and two ends of an oxygenation membrane wire contained in the oxygenation module respectively penetrate through the first sealing layer and the second sealing layer and are respectively communicated with the first chamber and the second chamber;

and the temperature control module is arranged in the shell, is positioned at the downstream of the oxygenation module along the flow direction of blood, and the side wall of the temperature control module is communicated with the blood outlet.

2. The oxygenator of claim 1,

the first end cover is also provided with a third interface, and the second end cover is also provided with a fourth interface; one of the third interface and the fourth interface is a temperature control medium inlet, and the other is a temperature control medium outlet;

the first sealing layer and the first end cap further define a third chamber fluidly isolated from the first chamber, the second sealing layer and the second end cap further define a fourth chamber fluidly isolated from the second chamber;

and two ends of a temperature control membrane wire contained in the temperature control module respectively penetrate through the first sealing layer and the second sealing layer and are respectively communicated with the third cavity and the fourth cavity.

3. The oxygenator of claim 2, the blood inlet being provided on the first end cap; the oxygenation module is of a cylindrical structure, and the inner side wall of the oxygenation module is communicated with the blood inlet;

the temperature control module is also in a substantially cylindrical structure and is arranged on the outer side of the oxygenation module; the outer side wall of the temperature control module and the inner side wall of the shell are spaced to form a gap space, and the gap space is communicated with the blood outlet.

4. The oxygenator of claim 1, the blood outlet being disposed in the housing sidewall with the axis of the blood outlet being located inwardly of a tangent line; the tangent line is a line which is positioned on the same side of the central axis of the shell with the axis, is parallel to the axis and is tangent to the outer wall of the shell.

5. The oxygenator of claim 4, the blood outlet and the housing forming an acute corner segment therebetween, the acute corner segment being a rounded corner or an arc transition.

6. The oxygenator of claim 1 wherein the first end cap has an outwardly domed structure formed thereon, the blood inlet communicating with the domed structure, the domed structure having an air vent formed therein.

7. The oxygenator of claim 1, there being no other arbitrary structure between the oxygenation module and temperature control module.

8. The oxygenator of any one of claims 1-7, a ratio L/H of a thickness L of the oxygenation module in a radial direction to a height H thereof in an axial direction is between 0.525 and 1.562.

9. The oxygenator of claim 2,

a first isolating piece is arranged in the shell, and the oxygenation membrane wire is wound outside the first isolating piece; the first isolating piece is of a hollow cylindrical structure, the inner space of the first isolating piece is communicated with the blood inlet, and a first hole for blood to pass through is formed in the side wall of the first isolating piece;

a second isolating piece positioned between the oxygenation module and the temperature control module is arranged in the shell, the temperature control membrane wire is wound outside the second isolating piece, and a second hole for blood to pass through is formed in the side wall of the second isolating piece;

the ratio of the volume of the first hole to the volume of the space occupied by the first spacer is α 1, and the ratio of the volume of the second hole to the volume of the space occupied by the second spacer is α 2; alpha 1 > alpha 2.

10. The oxygenator of claim 9, said housing having a separation cone disposed therethrough in said first partition; and in the direction of pointing to the first end cover along the second end cover, the gap distance between the outer wall of the separation cone and the inner wall of the first isolating piece is gradually reduced.

11. The oxygenator of claim 10, the first end cap being formed with a circumferential flange extending to the first sealing layer, one end of the first partition connecting the separation cone and the other end connecting the circumferential flange, the circumferential flange and the first partition defining a blood diversion lumen housing the separation cone;

the blood diversion chamber includes a blood inlet region into which the separation cone partially extends; wherein, the blood inlet area is the area between the surface section of the first sealing layer opposite to the first end cover and the first end cover of the blood diversion cavity.

12. The oxygenator of claim 11, a ratio of a volume of the separation cone projecting into the blood inlet region to a volume of the blood inlet region is between 0.293 and 0.726.

13. The oxygenator of claim 12, the separation cone comprising a first cone segment proximate the first end cap, a cone head of the first cone segment passing beyond the first sealing layer into the circumferential flange, the cone head being between 0.012 and 0.546 centimeters from a top of the blood inlet region.

14. The oxygenator of claim 12 or 13, a ratio between a distance between a conical head of the first conical segment and a top of the blood inlet region and a height of the first conical segment is between 0.009 to 0.237.

15. The oxygenator of claim 13, the separation cone further comprising a second cone segment proximate the second end cap and connected to the first cone segment, the second cone segment being partially located within the first barrier; the taper angle of the first conical section is greater than the taper angle of the second conical section.

16. The oxygenator of claim 11, a minimum effective flow area of the blood inlet region being no less than a cross-sectional area of the blood inlet.